<template>
	<view class="tn-subsection-class tn-subsection" :class="[subsectionBackgroundColorClass]"
		:style="[subsectionStyle]">
		<!-- 滑块 -->
		<block v-for="(item, index) in listInfo" :key="index">
			<view class="tn-subsection__item tn-text-ellipsis" :class="[
          'section-item-' + index,
          noBorderRight(index)
        ]" :style="[itemStyle(index)]" @tap="click(index)">
				<view class="tn-subsection__item--text tn-text-ellipsis" :style="[textStyle(index)]">
					{{ item.name }}
				</view>
			</view>
		</block>
		<!-- 背景 -->
		<view class="tn-subsection__bg" :class="[itemBarClass]" :style="[itemBarStyle]"></view>
	</view>
</template>

<script>
	import componentsColorMixin from '../../libs/mixin/components_color.js'
	export default {
		mixins: [componentsColorMixin],
		name: 'tn-subsection',
		props: {
			// 模式选择
			// button 按钮模式 subsection 分段模式
			mode: {
				type: String,
				default: 'subsection'
			},
			// 组件高度
			height: {
				type: Number,
				default: 60
			},
			// tab的数据
			list: {
				type: Array,
				default () {
					return []
				}
			},
			// 当前活动tab的index
			current: {
				type: [Number, String],
				default: 0
			},
			// 激活时的字体颜色
			activeColor: {
				type: String,
				default: '#FFFFFF'
			},
			// 未激活时的字体颜色
			inactiveColor: {
				type: String,
				default: '#AAAAAA'
			},
			// 激活tab的字体是否加粗
			bold: {
				type: Boolean,
				default: false
			},
			backgroundColor: {
				type: String,
				default: '#F4F4F4'
			},
			// 滑块的颜色
			buttonColor: {
				type: String,
				default: '#01BEFF'
			},
			// 当mode为button时生效，圆角的值，单位rpx
			borderRadius: {
				type: Number,
				default: 10
			},
			// 是否开启动画
			animation: {
				type: Boolean,
				default: true
			},
			// 动画类型
			// cubic-bezier -> 贝塞尔曲线
			animationType: {
				type: String,
				default: ''
			},
			// 滑动滑块的是否，是否触发震动
			vibrateShort: {
				type: Boolean,
				default: false
			}
		},
		data() {
			return {
				// 列表数据
				listInfo: [],
				// 子元素的背景样式
				itemBgStyle: {
					width: 0,
					left: 0,
					backgroundColor: '#ffffff',
					height: '100%'
				},
				// 当前选中的滑块
				currentIndex: this.current,
				buttonPadding: 3,
				// 组件初始化的是否current变换不应该震动
				firstVibrateShort: true
			}
		},
		watch: {
			list: {
				handler(val) {
					this.listInfo = val.map((item, index) => {
						if (typeof item !== 'object') {
							let obj = {
								width: 0,
								name: item
							}
							return obj
						} else {
							item.width = 0
							return obj
						}
					})
				},
				immediate: true,
				deep: true
			},
			current: {
				handler(val) {
					this.currentIndex = val
					this.changeSectionStatus(val)
				},
				immediate: true
			}
		},
		created() {
			// 将list的数据，传入listInfo数组
			// 接受直接数组形式，或者数组元素为对象的形式，如：['开启', '关闭'],或者[{name: '开启'}, {name: '关闭'}]
			this.listInfo = this.list.map((item, index) => {
				if (typeof item !== 'object') {
					let obj = {
						width: 0,
						name: item
					}
					return obj
				} else {
					item.width = 0
					return obj
				}
			})
		},
		computed: {
			// 设置mode=subsection时，滑块没有样式
			noBorderRight() {
				return index => {
					if (this.mode !== 'subsection') return
					let clazz = ''
					// 不显示右边的边距
					if (index < this.list.length - 1) clazz += ' tn-subsection__item--none-border-right'
					// 显示整个组件的左右边圆角
					if (index === 0) clazz += ' tn-subsection__item--first'
					if (index === this.list.length - 1) clazz += ' tn-subsection__item--last'
					return clazz
				}
			},
			// 文字的样式
			textStyle() {
				return index => {
					let style = {}
					// 设置字体颜色
					if (index === this.currentIndex) {
						style.color = this.activeColor
					} else {
						style.color = this.inactiveColor
					}
					// 字体加粗
					if (index === this.currentIndex && this.bold) style.fontWeight = 'bold'
					// 文字大小
					style.fontSize = (this.fontSize || 26) + this.fontUnit
					return style
				}
			},
			// 每个分段器item的样式
			itemStyle() {
				return index => {
					let style = {}
					if (this.fontSizeStyle) {
						style.fontSize = this.fontSizeStyle
					}
					if (this.mode === 'subsection') {
						// 设置border的样式
						style.borderColor = this.buttonColor
						style.borderWidth = '1rpx'
						style.borderStyle = 'solid'
					}
					return style
				}
			},
			// mode = button时，设置外层view的样式
			subsectionStyle() {
				let style = {}
				style.height = this.height + 'rpx'
				if (this.mode === 'button') {
					style.backgroundColor = this.backgroundColorStyle
					style.padding = `${this.buttonPadding}px`
					style.borderRadius = `${this.borderRadius}rpx`
				}
				return style
			},
			// mode = button时，设置外层view的背景class
			subsectionBackgroundColorClass() {
				let clazz = ''
				if (this.mode === 'button' && this.backgroundColorClass) {
					clazz = this.backgroundColorClass
				}
				return clazz
			},
			itemBarClass() {
				let clazz = ''
				const buttonBgClass = this.$tn.color.getBackgroundColorInternalClass(this.buttonColor)
				if (this.animation) {
					clazz += ' tn-subsection__bg__animation'
					if (this.animationType) {
						clazz += ` tn-subsection__bg__animation--${this.animationType}`
					}
				}
				if (buttonBgClass) {
					clazz += ` ${buttonBgClass}`
				}
				return clazz
			},
			// 滑块样式
			itemBarStyle() {
				let style = {}
				const buttonBgStyle = this.$tn.color.getBackgroundColorStyle(this.buttonColor)
				if (buttonBgStyle) {
					style.backgroundColor = this.buttonColor
				}
				style.zIndex = 1
				if (this.mode === 'button') {
					style.borderRadius = `${this.borderRadius}rpx`
					style.bottom = `${this.buttonPadding}px`
					style.height = (this.height - (this.buttonPadding * 4)) + 'rpx'
					style.zIndex = 0
				}
				return Object.assign(this.itemBgStyle, style)
			}
		},
		mounted() {
			// 等待加载组件完成
			setTimeout(() => {
				this.getTabsInfo()
			}, 10)
		},
		methods: {
			// 改变滑块样式
			changeSectionStatus(val) {
				if (this.mode === 'subsection') {
					// 根据滑块在最左和最右时，显示对应的圆角
					if (val === this.list.length - 1) {
						this.itemBgStyle.borderRadius = `0 ${this.buttonPadding}px ${this.buttonPadding}px 0`
					}
					if (val === 0) {
						this.itemBgStyle.borderRadius = `${this.buttonPadding}px 0 0 ${this.buttonPadding}px`
					}
					if (val > 0 && val < this.list.length - 1) {
						this.itemBgStyle.borderRadius = '0'
					}
				}
				// 更新滑块的位置
				setTimeout(() => {
					this.itemBgLeft()
				}, 10)
				if (this.vibrateShort && !this.firstVibrateShort) {
					// 使手机产生短促震动，微信小程序有效，APP(HX 2.6.8)和H5无效
					// #ifndef H5
					uni.vibrateShort();
					// #endif
				}
				this.firstVibrateShort = false
			},
			// 获取各个tab的节点信息
			getTabsInfo() {
				let view = uni.createSelectorQuery().in(this)
				for (let i = 0; i < this.list.length; i++) {
					view.select('.section-item-' + i).boundingClientRect()
				}
				view.exec(res => {
					// 如果没有获取到，则重新获取
					if (!res.length) {
						setTimeout(() => {
							this.getTabsInfo()
							return
						}, 10)
					}
					// 将每个分段器的宽度放入listInfo中
					res.map((item, index) => {
						this.listInfo[index].width = item.width
					})
					// 初始化滑块的宽度
					if (this.mode === 'subsection') {
						this.itemBgStyle.width = this.listInfo[0].width + 'px'
					} else if (this.mode === 'button') {
						this.itemBgStyle.width = this.listInfo[0].width + 'px'
					}

					// 初始化滑块的位置
					this.itemBgLeft()
				})
			},
			// 设置滑块的位置
			itemBgLeft() {
				let left = 0
				// 计算当前活跃item到组件左边的距离
				this.listInfo.map((item, index) => {
					if (index < this.currentIndex) left += item.width
				})
				// 根据不同的模式，计算滑块的位置
				if (this.mode === 'subsection') {
					this.itemBgStyle.left = left + 'px'
				} else if (this.mode === 'button') {
					this.itemBgStyle.left = left + this.buttonPadding + 'px'
				}
			},

			// 点击事件
			click(index) {
				// 不允许点击当前激活的选项
				if (index === this.currentIndex) return
				this.currentIndex = index
				this.changeSectionStatus(index)
				this.$emit('change', {
					index: Number(index),
					name: this.listInfo[index]['name']
				})
			}
		}
	}
</script>

<style lang="scss" scoped>
	.tn-subsection {
		display: flex;
		flex-direction: row;
		align-items: center;
		overflow: hidden;
		position: relative;

		&__item {
			display: flex;
			flex-direction: row;
			flex: 1;
			text-align: center;
			font-size: 26rpx;
			height: 100%;
			align-items: center;
			justify-content: center;
			color: #FFFFFF;
			padding: 0 6rpx;


			&--text {
				transition: all 0.3s;
				color: #FFFFFF;
				display: flex;
				flex-direction: row;
				align-items: center;
				position: relative;
				z-index: 3;
			}

			&--first {
				border-top-left-radius: 8rpx;
				border-bottom-left-radius: 8rpx;
			}

			&--last {
				border-top-right-radius: 8rpx;
				border-bottom-right-radius: 8rpx;
			}

			&--none-border-right {
				border-right: none !important;
			}
		}

		&__bg {
			background-color: $tn-main-color;
			position: absolute;
			z-index: -1;
			transition-property: all;
			transition-duration: 0s;
			transition-timing-function: linear;

			&__animation {
				transition-duration: 0.25s !important;

				&--cubic-bezier {
					transition-timing-function: cubic-bezier(0.68, -0.55, 0.265, 1.55) !important;
				}
			}
		}
	}
</style>